ML18005A215

LER 87-060-00:on 871015,isolation Valves Between RCS & RHR Pump Suctions Closed on Two Separate Occasions.Caused by Shorting of Test Equipment Output & Battery Failure in Test Equipment.Revs to Procedures Being considered.W/871116 Ltr

ML18005A215
Person / Time
Site:	Harris
Issue date:	11/16/1987
From:	Watson R CAROLINA POWER & LIGHT CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
HO-870559-(O), LER-87-060, LER-87-60, NUDOCS 8711230296
Download: ML18005A215 (6)

Text

REGULA Y INFORMATION DISTRIBUTID, YSTEM (RIDS)

( ACCESSION NBR: 8711230296 DOC. DATE: 87/11/16 NOTARIZED: NO DOCKET FACIL:"50-400 Shearon Harris Nuclear PoUjer P lanti Unit ii Carolina 05000400

• UTH. NAt1E AUTHOR AFFILIATION WATSON/R. A. Carolina Power D~ Light Co.

REC IP. NAME REC I P IENT AFF IL-IAT ION

SUBJECT:

LFR 87-060-00: on 871015~ isolation valves between RCS 5 RHR pump suctions closed on two separate occasions. Caused bg shorting of test equipment output ~D. battery failure in test equipment. Test procedures revised..W/871116 ltr.

DISTRIBUTION CODE: IE22D COPIES RECEIVED: LTR i ENCL SIZE:

TITLE: 50. 73 Licensee Event Report (LER)I Incident Rpti etc.

NOTES: Application for permit reneeal f iled. 05000400 RECIPIENT COPIES REC lP I ENT COP IES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD2-i LA 1 1 PD2-1 PD 1 BUCKLEYI 9 1 1 INTERNAL: ACRS MI CHELSON 1 ACRS MOELLER AEOD/DQ* i 1 AEOD/DSP/N*S 1 AEOD/DSP/ROAB 2 2 AEOD/DSP/TP*B 1 1 ARM/DCTS/DAB 1 DFDRO 1 NRR/DEBT/ADS 0 NRR/DEST/CEB i 1 NRR/DEST/FLB i 1 NRR/DEST/ICSB NRR/DEST/MEB 1 1 NRR/DEST/MTB 1 1 NRR/DEST/PSB 1 NRR/DEST/RSB 1 NRR/DEST/SGB 1 NRR/DLPG/HFB 1 NRR/DLPG/GAB 1 NRR/DOE*/E*B NRR/DREP/RAB 1 NRR/DREP/RPB 2 2 1 NRR/PMAS/ILRB i 1 RE FI 02 RES DEPY GI i TELFORDI J RES/DE/E I 8 i 1 RGN2 F I LE 01 1 1 EXTERNAL: EG8cG GROHI M 5 5 H ST LOBBY WARD 1 1 LPDR 1 1 NRC PDR 1 1 NSIC HARRISr J 1 1 NSIC MAYST G 1 i TOTAL NUMBER OF COPIES REQUIRED: LTTR 45 ENCL 44

NRC Form 388 US. NUCLEAR REOULATORY COMMISSION (943) APPROVEO OMB NO, 31500108 EXPIRES: 8/31/88 LICENSEE EVENT REPORT (LER)

DOCKET NUMBER (2) PACE 3 FACILITYNAME (I)

SHEARON HARRIS NUCLEAR POWER PLANT UN 0 5 0 0 0 1 OF ISOLATION OF RESIDUAL HEAT REMOVAL SYSTEM (RHR) DURING TESTING OF VALVE INTERLOCKS EVENT DATE (5I LER NUMBE'R (6) REPORT DATE (7) OTHER FACILITIES INVOLVED IS)

MONTH YEAR YEAR SFOVENTIAL MONTH OAY YEAR FACILITYNAMES DOCKET NVMBERIS)

DAY NUMSER n..i. NVM88rl ~

0 5 0 0 0 0 5 0 0 0 THIS REpoRT Is sUBMITTED PURSUANT To THE REDUIREMENTB oF 10 cF R ()r Icneclt one or more of mr follovrlnpJ (11)

OPERATINO MODE (9) 20A02(8) . 20AOS(c) 50.73(e) (2) (Ivl 73.7) III)

POWER 20AOSI ~ )(1)(I) 50.38(e) (1) 50.73(e)(2)(v) 73.71(c)

LEVEL (10) 0 20AOS(e) (1 )(II) 50.38(cl(2) 50.73(e) (2)(vQ) OTHER ISprclfy In Abrcrect briovvrnd In Tert, HRC Potm 20AOS( ~ ) (1)(III) 50.73(e l (2)(I) 50,73(e) (2) (v) Ill (Al 366A)

)L 20AOB(e)(1)Bvl 50.73(e) (2) (II) 50.73(e) (2)(vill)(8)

I 20AOS( ~ )(1)(v) 50 73(e) (2) IIB) 50,73( ~ ) (2) (r I LICENSEE CONTACT FOR THIS LER (12)

NAME TELEPHONE NUMBER AREA CODE COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13) 9 19'62 -27 1 r gN. ". o NN CAUSE SYSTEM COMPONENT MANUFAG TVRER EPORTABLE TO NPROS 3&6

,.v.S,.~..g%

% CAUSE SYSTEM COMPONENT MANUFAC TURER EPORTABLE; TO NPRDS

~)59'95%@j:-:'UPPLEMENTAL REPORT EXPFCTED (lel MONTH DAY YEAR EXPECTED SUBMISSION DATE (15)

YES Ilfyrr, complrtr EXPECTED SIISMISSIOH DATE/ NO ABSTRACT ILlmlt to le00 rpecer, I 8, epprorlmetrty filrern rlnple.rpecr typevvrltten linml (18)

ABSTRACT:

On October 15, 1987, with the plant in Mode 5, 130'F and depressurized, during the performance of Operations Surveillance Test (OST) 1071, Residual Heat Removal (RHR) Suction Valve Interlock Test, the isolation valves between the Reactor Coolant System (RCS) and the RHR pump suctions closed on two separate occasions. This resulted in the unavailability of the RHR system to remove residual heat. The steam generators were available to serve as the RCS heat sink.

The cause of the first isolation event was apparently due to momentarily shorting the test equipment output, while the test equipment, a Ronan X-85 Calibrator, was being installed. The second event was caused by a battery failure in the test equipment due to excessive discharge. In both cases, the operator recognized the event and was able to restore RHR operation in five minutes and fifteen minutes, respectively.

Revisions to the test procedure which would prevent recurrence of the event are under consideration.

87i1230296 87iiih PDR ADOCK 05D00400

$ t> lI NRC Form 388 (943) 8 PDR

US. NUCLEAR REOULATORY COMMISSION NRC fore 35BA APPROVEO OMB NO. 3)d0-0105 (043)

LICENSEE EVENT REPORT ILERI TEXT CONTINUATION EXPIRES: BI31/Bd OOCKET NUMBER (1) ~ AOE (3) fACILITYNAME (ll , LER NUMBER (d)

CCQVCNTIAL RCVICION VCAR NVM CR NVM CR SHEARON HARRIS NUCLEAR POWER PLANT UNIT 1 0 5 0 0 0 4 0 0 8 7 0 6 0 0 0 0 2 QF 0 TEXT IIP IRoro Neco (r IPCNCCIL INP aCCCCNMI HID AIIII3BSC 3) (ITI INITIAL CONDITIONS:

The plant was stable in Mode 5, COLD SHUTDOWN, with Reactor Coolant System (RCS) at approximately 130'F and depressurized to atmospheric pressure. The unit was in a planned outage for surveillance testing, maintenance, and modification activities.

EVENT DESCRIPTION:

Personnel were preparing for the performance of Operations Surveillance Test (OST) 1071, Residual Heat Removal Suction Valve Interlock Test. This procedure verifies the operability of the high pressure interlock which closes the Residual Heat Removal (RHR) pump suction valves (EIIS:BP) on a high RCS pressure, and also prevents them from being inadvertently opened when RCS pressure'is high. This interlock is a requirement of Technical Specification 3.5.2, Emergency Core Cooling System, Surveillance Requirement 4.5.2.d.l.

At 0740, on October 15, 1987, while technicians were installing the test rig (EIIS:None Applicable) (Manufacturer'.Ronan Engineering Model: .

X-,85 Calibrator), an apparent momentary short of the Ronan Output Signal caused a spurious signal to be generated which closed the RHR isolation valves (EIIS:BP), interrupting system flow. The operator observed the low flow annunciator for the RHR system, and observed that the valves had closed. The test equipment was removed, and within five minutes RHR operation was reestablished.

Power was removed from the isolation valve in the operating RHR train while the test equipment was reinstalled, so that if the event reoccurred, the operating RHR train would not be affected. The test rig was successfully installed, and no isolation occurred on the standby RHR train. The event was reviewed for potential reportability per plant procedure AP-615, NRC Reporting Requirements, and it was concluded that the event was not reportable based on the availability of the steam generators as an RCS heat sink per Technical.

Specification 3.4.1.4.1. A Significant Operational Occurrence Report (SOOR) was written by the operators to document the event for management review.

During the day, completion of the test procedure was delayed due to other ongoing evolutions to support the outage. At 2122, the RHR isolation valves closed a second time, when the battery in the Ronan test equipment went dead, causing a high pressure test signal to be generated spuriously. Again, plant personnel recognized what had occurred, removed the test equipment, and within fifteen minutes had restored RHR operation.

On October 16, 1987, Regulatory Compliance personnel reviewed the SOOR written against the event, and determined that it was reportable per 10CFR50.72. The required notification'was made that day.

NRC CORM SCCA RU.S.GPO.IQBBWB25 ddd(Cdd (343l

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U.S. NUCLEAR REOULATORY COMMISSION NRC Form SSEA 3)80&104 (94)$ )

LICENSEE EVENT REPORT ILER) TEXT CONTINUATION APPROVED OMS NO.

EXPIRES: 8/31/88 OOCIIET NUMSER I2) LER NUMBER IS) PACE IS)

FACILITYNAME 11)

SEOVENTIAL REVISION YEAR NUM EII SHEARON HARRIS NUCLEAR POWER PLANT NI/MOER UNIT 1 OF 0 5 0 0 0 TEXT /R moro Nmce /I EPE)rord INo ~ /R/O/Nr/ HRC %%drrrr Pgl'I/1)T)

CAUSE:

The cause of the first failure at 0740 was the electrical transient induced while installing the test rig. An investigation of the test circuit and procedure for installation showed that (with the channel not in test) a momentary short of the Ronan output caused the Ronan output signal to spike high. This was determined by testing the test equipment hookup with an operable test loop under several different conditions. I The cause of the second failure at 2122 was a battery failure due to excessive discharge occurring when the test rig was Left in place for a long period oi time. Tests showed that as the Ronan battery discharged, a spike of 10.88V occurred at the end of the discharge. This is an apparent inherent characteristic of this Ronan.

DESIGN INFORMATION:

The design of the RHR system is that each pump suction is connected to an RCS hot leg with two in series isolation valves, each of which is powered from a separate electrical train. That is, each of two RHR trains has an A train isolation valve and a B train isolation valve. There are two RCS pressure transmitters which, on a high RCS pressure, will close one of the two isolation valves in each RHR train, and will prevent them from being reopened until pressure is sufficiently low. The system is designed in this manner such that no single failure of a pressure 'transmitter, electrical power train or isolation valve will inhibit isolation of RHR from the RCS on high pressure, so that the integrity of the RHR system is protected. This interlock is required to be operable in Modes 1 through 4 when the RHR system is used for low pressure safety injection.

SAFETY SIGNIFICANCE:

'A'ingle failure of test equipment caused the isolation and temporary inoperability of both RHR trains. During the event, the steam generators were available as an RCS heat sink, and if RHR cooling had not been restored, from the residual heat could have been removed by releasing steam generators. Operators were able to quickly determine that the RHR system was not available, and take prompt action to restore it to service.

No similar events have previously occurred at the Harris Plant.

This event is being reported in accordance with 10CFR50.73(a)(2)(v) and (vi) as a single event which caused the unavailability of a system designed to remove residual heat, and redundant equipment in the same system was not available to perform the same function.

NRC FORM 844A O U.S.OPO.1088 &b24 ddd/4dd 1042)

NRC fO?IA 388A UA. NUCLEAR REOULATORY COMMISSION 1943 l LICENSEE EVENT REPORT (LER) TEXT CONTINUATION APPROVED OMS NO. 3150WIOC EXPIRES: 8/31/88 fACILITYNAME 11l DOCKET NUMSER 12l LER NUMSER 1SI PACE 131

<wO/ 4CVOION SHEARON HARRIS NUCLEAR POWER PLANT YEAR SEQUENTIAL g@ NVM Ch  :.G?? NIZAM 1 4 UNIT 1 0 5 0 0 0 OF TEXT ///'/ho/o cfoco /I /oyo/44/ off f/I/ooo/HRC fc//?I 38dlS/1171 CORRECTIVE ACTION:

1. The procedure for testing the RHR isolation valve interlocks will be reviewed and revised as appropriate to prevent recurrence of this event. Under consideration is the removaL of power to the isolation valves for the RHR train in service while the test equipment is in installed and in place, so that failures in the test equipment wilL not isolate the operating train.

2. The OST procedure is to be revised to place the channel. in test before hooking up the test equipment. This is normaL procedure for I&C Calibrations.

3. A caution statement to prohibit Leaving the test equipment installed for more than one shift will be added to the OST Procedure.

NhC PORM 3CCA *U.S OPO:19884 82l 838/idd 1943 I

Carolina Power & Light Company HARRIS NUCLEAR PROJECT P.O. Box 165 New Hill, NC 27562

~ 6 1987 File Number: SHF/10-13510C Letter Number: HO-870559 (0)

U.S. Nuclear Regulatory Commission ATTN: NRC Document Control Desk Washington, DC 20555 SHEARON HARRIS NUCLEAR POWER PLANT UNIT 1 DOCKET NO. 50-400 LICENSE NO. NPF-63 LICENSEE EVENT REPORT 87-060-00 Gentlemen.'n accordance with Title 10 to the Code of Federal Regulations, the enclosed Licensee Event Report is submitted. This report fulfills the requirement for a written report within thirty (30) days of a reportable occurrence and is in accordance with the format set forth in NUREG-1022, September, 1983.

Very truly yours, R. A. Watson ice President Harris Nuclear Project RAW'ddl Enclosure cc'Dr. J. Nelson Grace (NRC RII)

Mr. B. Buckley*(NRR)

Mr. G. Maxwell (NRC SHNPP)

MEM/LER-87-060/1Page 1/OS1